Characterization of the Activation-Relaxation Technique: Recent Results on Models of Amorphous Silicon

2001 ◽  
Vol 677 ◽  
Author(s):  
Rachid Malek ◽  
Normand Mousseau ◽  
G. T. Barkema
Keyword(s):  
Amorphous Silicon ◽  
Detailed Analysis ◽  
Saddle Points ◽  
Amorphous Semiconductors ◽  
Relaxation Technique ◽  
Energy Landscapes ◽  
Lennard Jones ◽  
Wide Range

ABSTRACTThe activation-relaxation technique (ART) is a method for finding saddle points in high-dimen- sional energy landscapes. ART has already been applied to a wide range of materials including amorphous semiconductors, Lennard-Jones glasses, and proteins. In spite of its successes, a number of fundamental questions remain to be answered regarding the biases associated with its sampling of the saddle points. We present here results of a detailed analysis of the biases in the simulation of amorphous silicon. We focus in particular on the biases of the method in sampling saddle points, the completeness of the sampling and the sensitivity of these quantities to variations of the different parameters.

Magnetic Resonance Probes Of Band Tail States And Defects In Tetrahedrally Coordinated Amorphous Semiconductors

2002 ◽  
Vol 715 ◽  
Author(s):  
P. C. Taylor
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Amorphous Semiconductors ◽  
Dangling Bonds ◽  
Band Tail ◽  
Wide Range ◽  
Recombination Processes ◽  
Staebler Wronski Effect ◽  
Hydrogenated Amorphous ◽  
Kinetics Of

AbstractRecent electron spin resonance (ESR) results relating to (1) recombination processes for optically excited electrons and holes in tetrahedrally coordinated amorphous semiconductors and (2) kinetics of metastable defects (dangling bonds associated with the Staebler-Wronski effect) in hydrogenated amorphous silicon (a-Si:H). With regard to recombination processes, ESR measurements have been performed over a wide range of excitation intensities (nW/cm2 to W/cm2) on hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous germanium (a-Ge:H). The kinetics can be studied down to carrier densities as low as 1014 cm-3. The longtime decay curves show that at large carrier separation (1) the random distribution of optically excited electrons and holes is subject to the condition of charge neutrality, and (2) the decays are universal and independent of the densities of localized, band-tail states. With regard to the metastable defects in a-Si:H, the kinetics of the production and thermal annealing of silicon dangling bonds have been measured at temperatures between 25 and 480 K using ESR. Below about 150 K the measurement of the dangling bonds is masked by long-lived, band tail carriers that accumulate with time. The production rate for silicon dangling bonds decreases with decreasing temperature and is nearly temperature independent below approximately 100 K. Defects created by 10 hours of irradiation below 100 K anneal almost completely at 300 K. In a- Ge:H, the first measurements of optically induced, metastable germanium dangling bonds have been made.

On the Margins of Modernism

2017 ◽  
Author(s):  
Christopher Rosenmeier
Keyword(s):  
Short Stories ◽  
Detailed Analysis ◽  
Chinese Literature ◽  
Popular Literature ◽  
Extensive Study ◽  
Wide Range ◽  
Chinese Fiction ◽  
Scant Attention ◽  
Narrative Techniques ◽  
Chinese Writing

Xu Xu and Wumingshi were among the most widely read authors in China during and after the Second Sino-Japanese War (1937–1945). Despite being an integral part of the Chinese literary scene, their bestselling fiction has, however, been given scant attention in histories of Chinese writing. This book is the first extensive study of Xu Xu and Wumingshi in English or any other Western language and it re-establishes their importance within the popular Chinese literature of the 1940s. Their romantic novels and short stories were often set abroad and featured a wide range of stereotypes, from pirates, spies and patriotic soldiers to ghosts, spirits and exotic women who confounded the mostly cosmopolitan male protagonists. Christopher Rosenmeier’s detailed analysis of these popular novels and short stories shows that such romances broke new ground by incorporating and adapting narrative techniques and themes from the Shanghai modernist writers of the 1930s, notably Shi Zhecun and Mu Shiying. The study thereby contests the view that modernism had little lasting impact on Chinese fiction, and it demonstrates that the popular literature of the 1940s was more innovative than usually imagined, with authors, such as those studied here, successfully crossing the boundaries between the popular and the elite, as well as between romanticism and modernism, in their bestselling works.

Features of optative modality in Macedonian language (with emphasis on the functionalities of independent da-construction)

2020 ◽  
pp. 301-323
Author(s):  
Natalya I. Kikilo ◽  
Keyword(s):  
Detailed Analysis ◽  
Present Article ◽  
Literary Language ◽  
Natural Context ◽  
Wide Range ◽  
Verb Forms ◽  
Text Types ◽  
The Future ◽  
The Subject ◽  
Ritual Context

In the Macedonian literary language the analytic da-construction used in an independent clause has a wide range of possible modal meanings, the most common of which are imperative and optative. The present article offers a detailed analysis of the semantics and functions of the Macedonian optative da-construction based on fiction and journalistic texts. The first part of the article deals with the specificities of the optative as a category which primarily considers the subject of a wish. In accordance with the semantic characteristics of this category, optative constructions are used in those discourse text types where the speakers are explicitly designated (the most natural context for the optative is the dialogue). The analysis of the Macedonian material includes instances of atypical usage of the optative da-construction, in which the wish of the subject is not apparent and thereby produces new emotional tonalities perceptible to the reader of a fiction/journalistic text. The study describes Macedonian constructions involving two different verb forms: 1) present tense form (da + praes) and 2) imperfective form (da + impf). These constructions formally designate the hypothetical and counterfactual status of the optative situation, respectively. Thus, the examples in the analysis are ordered according to two types of constructions, which reflect the speaker’s view on the probability of the realisation of his/her wish. Unrealistic wishes can be communicated through the present da-construction, while the imperfective construction denotes situations in which the wish can be realised in the future. The second part of the article is devoted to performative optative da-constructions, which express formulas of speech etiquette, wishes and curses. The analysis demonstrates that these constructions lose their magical functions, when used outside of the ritual context, and begin to function as interjections.

MALAT1 as a Versatile Regulator of Cancer: Overview of the updates from Predatory role as Competitive Endogenous RNA to Mechanistic In-sights

2020 ◽  
Vol 20 ◽  
Author(s):  
Ammad Ahmad Farooqi ◽  
Evangelia Legaki ◽  
Maria Gazouli ◽  
Silvia Rinaldi ◽  
Rossana Berardi
Keyword(s):  
Molecular Biology ◽  
Detailed Analysis ◽  
Signaling Pathways ◽  
Individualized Medicine ◽  
Signaling Cascades ◽  
Oncogenic Signaling ◽  
Non Coding Rnas ◽  
Oncogenic Signaling Pathways ◽  
Competitive Endogenous Rna

: Central dogma of molecular biology has remained cornerstone of classical molecular biology but serendipitous discovery of microRNAs (miRNAs) in nematodes paradigmatically shifted our current understanding of the intricate mech-anisms which occur during transitions from transcription to translation. Discovery of miRNA captured tremendous attention and appreciation and we had witnessed an explosion in the field of non-coding RNAs. Ground-breaking discoveries in the field of non-coding RNAs have helped in better characterization of microRNAs and long non-coding RNAs (LncRNAs). There is an ever-increasing list of miRNA targets which are regulated by MALAT1 to stimulate or repress expression of tar-get genes. However, in this review our main focus is to summarize mechanistic insights related to MALAT1-mediated regu-lation of oncogenic signaling pathways. We have discussed how MALAT1 modulated TGF/SMAD and Hippo pathways in various cancers. We have also comprehensively summarized how JAK/STAT and Wnt/β-catenin pathways stimulated MALAT1 expression and consequentially how MALAT1 potentiated these signaling cascades to promote cancer. MALAT1 research has undergone substantial broadening however, there is still a need to identify additional mechanisms. MALAT1 is involved in multi-layered regulation of multiple transduction cascades and detailed analysis of different pathways will be helpful in getting a step closer to individualized medicine.

Polymer Chemistry

2004 ◽  
Keyword(s):  
Conducting Polymers ◽  
Liquid Crystalline ◽  
Polymer Chemistry ◽  
Chain Growth ◽  
Crystalline Polymers ◽  
Wide Range ◽  
Cyclic Oligomers ◽  
Step Growth

Polymer Chemistry: A Practical Approach in Chemistry has been designed for both chemists working in and new to the area of polymer synthesis. It contains detailed instructions for preparation of a wide-range of polymers by a wide variety of different techniques, and describes how this synthetic methodology can be applied to the development of new materials. It includes details of well-established techniques, e.g. chain-growth or step-growth processes together with more up-to-date examples using methods such as atom-transfer radical polymerization. Less well-known procedures are also included, e.g. electrochemical synthesis of conducting polymers and the preparation of liquid crystalline elastomers with highly ordered structures. Other topics covered include general polymerization methodology, controlled/"living" polymerization methods, the formation of cyclic oligomers during step-growth polymerization, the synthesis of conducting polymers based on heterocyclic compounds, dendrimers, the preparation of imprinted polymers and liquid crystalline polymers. The main bulk of the text is preceded by an introductory chapter detailing some of the techniques available to the scientist for the characterization of polymers, both in terms of their chemical composition and in terms of their properties as materials. The book is intended not only for the specialist in polymer chemistry, but also for the organic chemist with little experience who requires a practical introduction to the field.

Synthesis and Characterization of Halogenated Amorphous Silicon via a Novel Glow Discharge Process

1998 ◽  
Vol 10 (1) ◽  
pp. 366-371 ◽  
Author(s):  
Oscar H. Giraldo ◽  
William S. Willis ◽  
Manuel Márquez ◽  
Steven L. Suib ◽  
Yuji Hayashi ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Amorphous Silicon ◽  
Synthesis And Characterization ◽  
Discharge Process

scholarly journals Organelle Genetics in Plants

2021 ◽  
Vol 22 (4) ◽  
pp. 2104
Author(s):  
Pedro Robles ◽  
Víctor Quesada
Keyword(s):  
Rna Editing ◽  
Posttranscriptional Regulation ◽  
Genome Engineering ◽  
Plant Mitochondria ◽  
Plastid Dna ◽  
Chloroplast Genomes ◽  
Wide Range ◽  
Organelle Genetics ◽  
Selection Of

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.

scholarly journals Characterization of a Novel CaCO3-Forming Alkali-Tolerant Rhodococcus erythreus S26 as a Filling Agent for Repairing Concrete Cracks

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2967
Author(s):  
Seunghoon Choi ◽  
Sungjin Park ◽  
Minjoo Park ◽  
Yerin Kim ◽  
Kwang Min Lee ◽  
...  
Keyword(s):  
Building Materials ◽  
Culture Fluid ◽  
Natural Phenomenon ◽  
Environment Friendly ◽  
Wide Range ◽  
Filling Agent ◽  
Calcium Source ◽  
Alkali Tolerance ◽  
High Alkali

Biomineralization, a well-known natural phenomenon associated with various microbial species, is being studied to protect and strengthen building materials such as concrete. We characterized Rhodococcus erythreus S26, a novel urease-producing bacterium exhibiting CaCO3-forming activity, and investigated its ability in repairing concrete cracks for the development of environment-friendly sealants. Strain S26 grown in solid medium formed spherical and polygonal CaCO3 crystals. The S26 cells grown in a urea-containing liquid medium caused culture fluid alkalinization and increased CaCO3 levels, indicating that ureolysis was responsible for CaCO3 formation. Urease activity and CaCO3 formation increased with incubation time, reaching a maximum of 2054 U/min/mL and 3.83 g/L, respectively, at day four. The maximum CaCO3 formation was achieved when calcium lactate was used as the calcium source, followed by calcium gluconate. Although cell growth was observed after the induction period at pH 10.5, strain S26 could grow at a wide range of pH 4–10.5, showing its high alkali tolerance. FESEM showed rhombohedral crystals of 20–60 µm in size. EDX analysis indicated the presence of calcium, carbon, and oxygen in the crystals. XRD confirmed these crystals as CaCO3 containing calcite and vaterite. Furthermore, R. erythreus S26 successfully repaired the artificially induced large cracks of 0.4–0.6 mm width.

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